VulnerabilityPublished 27 Apr 2026

CVE-2026-33566: Japan Computer Emergency Response Team Coordination Center (JPCERT/CC) LogonTracer · Improper Neutralization of Special Elements in Data Query Logic

Affects Japan Computer Emergency Response Team Coordination Center (JPCERT/CC) LogonTracerSource CVE Database V5

Not known to be exploited · CVSS 4.3 Medium · patch available : update Japan Computer Emergency Response Team Coordination Center (JPCERT/CC) LogonTracer when convenient.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.0 base score

4.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 27 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Japan Computer Emergency Response Team Coordination Center (JPCERT/CC)LogonTracer	Affected =prior to v2.0.0	Fixed in–

AI-suggested

If you cannot patch yet, users should avoid loading untrusted or specially crafted Windows event log data into LogonTracer versions prior to 2.0.0.

Description

CVE-2026-33566 is a medium severity vulnerability in JPCERT/CC LogonTracer versions prior to 2.0.0. It involves improper neutralization of special elements in data query logic, specifically a cypher injection issue. If specially crafted Windows event log data is loaded, an attacker could alter the contents of the database. There is no confirmed patch or official remediation guidance available at this time. The vulnerability does not affect cloud services and no known exploits are reported in the wild.

Impact

The impact is limited to integrity, where an attacker can alter database contents by injecting malicious data through specially crafted Windows event logs. There is no impact on confidentiality or availability. The vulnerability requires user interaction and can be exploited remotely without privileges, but the attack complexity is low. No known exploits are reported in the wild.

Summary

This vulnerability in LogonTracer before version 2.0.0 allows specially crafted Windows event log data to cause cypher injection, leading to potential unauthorized alteration of the database contents. The issue stems from improper neutralization of special elements in the data query logic. The CVSS 3.0 base score is 4.3, reflecting a medium severity with network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, no confidentiality impact, limited integrity impact, and no availability impact.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 May 2026, 07:26 UTC

Technical details

References

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